Roof-covering.



rearra- ROOF-COVERING.

No Drawing.

of the fat and oil industries. All products thus obtained have as a natural consequence of their composltlon the one great disadvantage 1n common that they are very easily 7 combustible. Many attempts have been made to avoid this inconvenience by additions having for their For example, wateI -glass, ammonium salts, cement, graphite, asbestos'and iron have been proposed or used. All these additions, however are very deficient for the object in view.' They do not yield a product which'is practically incombustible' and should the roof "take fire' the materials made in this manner fail completely: This is due to the fact that under theinfluence of heat the impregnating matter which always has a comparatively low melting point flows away from the paper or felt, whereas the added material does not. Thus the'imp'regnating substance and the added material are separated so that the matter flowing away recovers its original vcombustibility. The

effect of the added materials used isthere:

fore quite illusory.

The present invention rests on the idea that the added material for preventing combustion should have physical properties (melting point for instance) as similar as possible to those of the impregnating substance and should be soluble in the latter so that together they form a homogeneous molten mass. In this manner the defect inherent in the addition hitherto used, namely separation which occurs above the melting point, is avoided; for if a material provided with an addition of the kind now in question is heated to a high temperature the impregnating substance and the addition melt together and the former remains as incombustible as before.

The invention consists therefore in mixing with the impregnating material, such a sub- Specification of Letters Patent.

' pregnated therewith. strip of a material made with such a mixture purpose tg diminish theeomexample benzin, added materials Patented Jan. 4, 1916.

Application filed January 15, 1914. Serial llTo. 812,314.

this purpose certain organic compounds of phosphoric acid included under the general term arylphosphates have proved V particularly suitable, namely the phosphoric acid esters of phenol and its substitution products. For example tr'ipheny' l p hggghate, any

"of the'g i ge yl and all possible mixed phenyl i D fl thd ahates. Moreover all p.os"s"fib"le"mirtures 0 simple and miXed esters; of phosphoric acid with phenol and .itss'ubsti'tution products maybe regarded as suitable for the purpose in question. These compounds or mixtures of compounds have the property of rendering incombustible is kindled it doesindeed inflame, but the flame is immediately extinguished, in conthe fabrics hitherto made continue to burn when kindled in the freely. hanging condition. y

The esters have the essential advantage that they are soluble in all If a freely hanging 7O roofing materials and the like which are im V fse aejnee of the action of the added material, v'vh'e'reas all proportions in'all.

impregnating materials such as tar, pitch, as

phalt or the like. Their melting points are comparatively close to nating materials. Se aration above the melting point therefore is not possible. These bodies dissolve inthosesohents which dissolve: the impregnating V substances, for benzene or. tl elike, "These besides having no tendenc to separate from the impregnating mass above the melting point, possess some other remarkably good properties which make them particularly suitable for the purpose in view and constitute by their introduction into the art an essential progress. 1. The pliability and softness of the material is not diminished by the addition of the substances in question. 2. The esters are very stable and do not decompose even when heated above 300 C. 3. The esters are insoluble in water so that they cannot be washed out by water or rain. 4:. It follows from 2 and 3 that such added materials are weather-proof. 5. The esters have no acid or alkaline reaction, so that materials impregnated with them can be laid upon metal supports. In respect of these propertles the substances aresuperior to the added maand ammonium salts are freely soluble in thoseof the impreg- Again magnesia ammonium phosphate, which indeed is insoluble in water containing ammonia, dissolves in pure water and is therefore washed. out in time by rain. Cement and water-glass have the disadvantage that they render the covering material brittle. If these substances are added to the molten impregnating mass they thicken it so that satisfactory saturation of the fiber is rendered diiiicult and the value of the material is diminished. None of these objections can occur if the added material. and the impregnated mass form a molten whole. lVhen iron is used there is the objection that it very quickly rusts and there is another objection, particularly noticeable in iron, but also to a greater or less degree in other materials, such as cement or graphite, namely that the weight of the material so comparatively great that its general applicability is aliected by the high transport costs connected with it.

The invention can be put into practice in various manners according to the conditions in which the substance for hindering combustion is to be used. The substance can be applied either in the molten or in the dissolved condition. The esters which come into consideration dissolve in the same solvents as dissolve the various impregnating materials, such as bent in, benzene or the like. illoreovcr, the ester or mixture of esters may be added. 1. To the impregnating mass or to the paper or "elt layer or to both at the same time at any suitable stage of: the manufacture. 2. To the 1naterial manufactured in the known manner but still combustible. In respect of these poss'bilities the following processes may be nan'ied: l. The paper or felt material may be saturated with molten ester or a mixture of esters or with a solution thereof, in a suitable solvent, and may then be treated with the impregnating mass. 2. The ester or mixtures of esters is melted together with the impregnating mass or dissolved together with the latter in a suitable solvent, such as benzin, benzene or the like, and the layer of paper or the like is impregnated with this molten mass or solution. Both the paper or felt and the impregnating mass may receive an addition of the ester or mixture ot esters and may then be further worked up. 4. The paper or felt is first treated with the impregnating mass in the usual manner and the still combustible material thus obtained is saturated with the molten or dissolved ester or mixture of esters and further worked up.

Having thus described my invention and the best means I know of carrying the same into practical eflect, I claim 1. A roofing material having a fibrous base impregnated with a combustible fusible body and a lire-proofing compound having a melting point substantially that of said body- 2. A rooting material having a fibrous base impregnated with a combustible fusible "ater-prooling body and a fireproofing body consisting of an arylphosphate having a melting point substantially that of said body. 3 V

3. A roofing material having a fibrous base impregnated with a combustible fusible water-proofing body and a lire-proofing body consisting of tri-phenylphosphate the melting point of which. is substantially that of said body.

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witness s.

OSKAR MATT Witnesses:

CONRAD Sonn BERT, Louis Vannoar.

Coaies of this atent ma be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. C. 

